How does desalination interact with the water cycle

Home » Solutions » Desalination » What is Desalination? Reverse Osmosis RO desalination uses the principle of osmosis to remove salt and other impurities, by transferring water through a series of semi-permeable membranes. Thermal desalination uses heat, often waste heat from power plantsor refineries, to evaporate and condense water to purify it. In the most advanced desalination plants, such as those built by IDE, water is pretreated in order to improve the efficiency of the plants.

RO desalination technology was initially developed in the late s, and has now evolved into the leading desalination technology globally. There are many different processes used in RO desalination, and a variety of factors come into play when selecting the appropriate solution for each situation — the quality of the source water, the desired quantity and quality of the water produced, pretreatment, energy requirements and disposal of concentrate.

RO can remove many types of molecules and ions, making it suited for potable and industrial uses. Standard osmosis involves a solvent such as water naturally moving from an area of low solute concentration, through a membrane, to an area of high solute concentration.

Seawater is pumped into the desalination plant from the ocean and passes through pre-treatment filtration to remove most of the large and small particles. The filtered seawater is then forced under pressure through special membranes whereby the osmosis process that normally occurs in nature is reversed. The pores in the membranes are so tiny that salt, bacteria, viruses and other impurities are separated from the seawater.

In essence they act like microscopic strainers. About half of the water that enters the plant from the sea becomes fresh drinking water. Accessed May 1, How 'bout a cool, refreshing cup of seawater? Geological Survey, U.

Department of the Interior. Source of vocabulary definitions with some adaptation. However, these contents do not necessarily represent the policies of the Department of Education or National Science Foundation, and you should not assume endorsement by the federal government. Why Teach Engineering in K? Find more at TeachEngineering.

Quick Look. Print this lesson Toggle Dropdown Print lesson and its associated curriculum. Suggest an edit. Discuss this lesson. Activities Associated with this Lesson Units serve as guides to a particular content or subject area. TE Newsletter. Subscribe to TE Newsletter. Summary Students learn about the techniques engineers have developed for changing ocean water into drinking water, including thermal and membrane desalination. They begin by reviewing the components of the natural water cycle.

They learn how processes can be viewed as systems, with unique objects, inputs, components and outputs, and sketch their own system diagrams to describe their own desalination plant designs. Engineering Connection Environmental engineers apply science and engineering principles to improve air, water and land resources; to provide healthy water, air and land for human habitation; and to remediate polluted sites.

Grades 6 - 8 Do you agree with this alignment? Water continually cycles among land, ocean, and atmosphere via transpiration, evaporation, condensation and crystallization, and precipitation, as well as downhill flows on land. Global movements of water and its changes in form are propelled by sunlight and gravity. Systems thinking involves considering how every part relates to others. Grades 6 - 8 More Details View aligned curriculum Do you agree with this alignment? An open-loop system has no feedback path and requires human intervention, while a closed-loop system uses feedback.

Colorado - Science Identify properties of substances in a mixture that could be used to separate those substances from each other Grade 7 More Details View aligned curriculum Do you agree with this alignment?

Develop and design a scientific investigation to separate the components of a mixture Grade 7 More Details View aligned curriculum Do you agree with this alignment? Water Cycle Remix Worksheet doc. Water Cycle Remix Worksheet pdf. Water Cycle Remix Worksheet Answers doc. Water Cycle Remix Worksheet Answers pdf. Water Desalination Presentation ppt. Water Desalination Presentation pdf. Middle School Activity. Saltwater Circuit Students build a saltwater circuit, which is an electrical circuit that uses saltwater as part of the circuit.

Saltwater Circuit. Upper Elementary Lesson. Fresh or Salty? Water Desalination Plant Students use a thermal process approach to design, build and test a small-scale desalination plant that is capable of significantly removing the salt content from a saltwater solution. Water Desalination Plant. Life Science. Physical Science. Click to view other curriculum aligned to this Performance Expectation. Develop a model to describe unobservable mechanisms. Already a subscriber? Sign in. Thanks for reading Scientific American.

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